Process for concentrating ore materials



Patented Mar. 2, 1943 rnocess roi r gonccn'msmc on TERIALS David Walker Jayne, In, Old Greenwich, Conn., Stephen Edward Erickson, Calumet, Minn., and Harold Milton Day, Cos Cob, Conn., assignors to American Cyanamid Company, New York, N. Y.. a corporation of Maine No Drawing. Application September 4, 1941,

Serial No. 409,531

13 Claims.

The present invention relates to mineral concentration. More particularly it relates to the use of a new class of reagents for selectively separating acidic minerals from ore materials.

Still more particularly this invention relates to the use of the products obtained by reacting a sulfonic acid salt of an alkylol amine with a higher fatty acid, fatty acid acylating agent or the like, or a sulfonic acid with an alkylolamide of a higher fatty acid at a temperature above 250 C., or other salts thereof as promoters or collectors for acidic minerals in froth flotation, film flotation, stratification, agglomeration, tabling, and related mineral separation processes. While the present invention is not limited to any particular ore concentrating process utilizing differential surface wettability principles or to any particular ore, its most important field of usefulness is in connection with froth flotation processes of separating silica or silicate minerals, such as mica, from non-metallic ores such as limestone, bauxite, barytes, ilmenite, calcite, and the like, and especially phosphate minerals, wherein the silicious gangue is floated away from the phosphate minerals.

In accordance with this invention natural ores or artificial materials comprising a mixture of acidic minerals with other mineral constituents are subjected to a separation or concentration process in the presence of a promoter for the acidic ore minerals, said promoter being a product obtained by heating an aromatic sulfonic acid salt of an alkylol amine with a higher fatty acid, or an aromatic sulfonic acid with an alkylolamide of a higher fatty acid, at a temperature above 250 C., to effect a separation of the acidic minerals from the other ore constituents.

The present invention relates to an entirely new class of promoting or collecting reagents for acidic minerals. These new reagents are promoters for negatively charged or acidic ore materials. The promoter action will, of course, vary with different acidic ore materials and with the different reagent combination used. In the past, various theories have been advanced as to the manner in which some acidic silicious promoters worked, one of which was that positively charged surface active ions had a strong afiinity for anionic or acidic minerals and hence they are Lil soluble products, provided satisfactory dispersion and distribution is effected. The present invention is accordingly not intended to be limited in any way to the use of a silica promoter which is highly ionized. The interaction between the surface of the silica and the promoter does not appear to be tied up exclusively with the presence of actual ions. The theory advanced in the prior art does not therefore appear to be correct as applied to silica flotation, or at least it does not appear to be a necessary factor in the present invention. We do not wish to advance any definite theory of action in silica flotation and the present invention is not intended to be limited to any particular theory of the so-called cationic reagen The compounds that have been found to have a selective filming attraction for acidic minerals and useful in carrying out the present invention include broadly the reaction products of an organic sulfonic acid, an alkylolamine, and a higher fatty acid, or a material equivalent to a higher fatty acid, wherein the reaction is carried out at a temperature in excess of 250 C.

In general we have found that the compounds may be prepared by three methods. The invensometimes loosely referred to in the art as cationic reagents.

We have found that it is not necessary to the present invention to use salts, as similar results are obtained with the substantially non-water tion, however, should not be limited to these three particular methods and it is contemplated that equivalent products produced by other methods will come within the scope of the invention.

The three general methods which we have found satisfactory for preparing our reagents, briefly outlined, are as follows:

A. By heating approximately equi-molecular proportions of an organic sulfonic acid salt of an alkylolamine and a fatty acid (or a mixture of fatty acids) to a temperature of about 270 C. with the removal of water. The reaction which probably takes place may be illustrated by the following equations between an aromatic sulfonic acid salt of monoethanolamine and a fatty acid.

250C. ((1) llOCHgGHzNH2.S0;H+RCOOH R-C 0-0-CIIz-CHzNH.4 SO H+Il 0 210 0. (b) R-CO-()CH2CH2-NII2.SO3II --i v 0-011. n-c +1120 N-CH: so3n In the above equations R represents an alkyl radical of a long chain fatty acid. represents an aromatic radical. such as benzene or naphthalene. The above reaction in all probability proceedsintwostepsasillustratemthatisto say,atabout250'C.onemoleculeofwater-is split out ofthearomaticsulfonlc acid salt of monoethanolamine'is Uponfurtherheatlngtoaboutflil'canother molecule ofwaterissplit out, aringclosure takes place and an oxasolineis probablyobtained B. The second method which may be employed for producing our reagents. comprises heating a mixture of an aromatic sulfonic acid, an alkylolamine and a fatty acid (or a mixture of fatty acid) at a temperature above 250' 0., preferably about 270' C. For example, when benzene sulfonic acid, monoethanolamine and myristic acid are mixed together, the sulfonic acid being a stronger acid than the myristic acid will prefer-.

acid.

when this process is employed, the alkylolamide of the fatty acid may be produced by reacting a primary or secondary alkylolamine with a fatty acid chloride, a glyceride or a fatty acid, or the like. Under certain conditions, dehydration may be effected at much lower temperatures, for example, if the reaction mixture is refluxed in toluene with the removal of the water of reaction.

While the compounds of the present invention I are most probably oxazolines, we do not desire to limit the invention by such a positive designation and prefer therefore to broadly include any or all products produced by the reaction of either aliphatic or aromatic sulfonic acid salts of alkylolamine with higher fatty acids, or a mixture of an aromatic sulfonic acid, I an alkylolamine and a higher fatty acid, or a mixture of an alkylolamide of a higher fatty acid and an aromatic sulfonic acid, at temperatures above 250 C.

The following examples are illustrative of methods which have been found suitable for preparing representative members of the compounds which are disclosed herein.

A. By heating an aromatic sulfonic acid salt of an alkylolamine and a higher fatty acid to 270 C. with the removal of water.

Example 1a A mixture of 218 grams (1 mol) of anhydrous benzene sulfonic acid salt of monoethanolamine and 214 grams (1 mol) of coconut oil fatty acids were heated to 270 C. in a short-neck flask fitted with a distilling condenser. 36 grams (2 mols) of water was collected as the distillate. The product was a waxy material, soluble in water to give a "foamy" solution. A

Example 2a Same procedure as Example 1a using 234 grams (1 mol) of anhydrous p-toluene sulfonic acid salt of monoethanolamine and 214 grams (1 mol) of 76 angers ooconntollfattyacids..Again36gram|(2mols ofwaterwasobtainedandtheproductwasslmi lartothatobtainedinlixamplel.

, Example 34 B. By heating a mixture of an aromatic acid, a! alkylolamine and a fatty acid to 270 C. wit! the removal of water.

Example 1b A mixture made up of 214 grams (1 mol) of coconut oil fatty acids, 61 grams (1 mol) of monoethanolamine and grams (1 mol) of p-toluene sulfonic acid monohydrate was heated tc 270 0. ma short-neck flask fitted with a distilling condenser. About 54 grams (3 mols) of water was collected as the distillate, 2 molecules of the water being split out in the course of the reaction, the third molecule being left present in the p-toluene sulfonic acid monohydrate. The prodnot obtained was a waxy material, soluble in water to give a foamy solution and otherwise identical to the product obtained in Example 1a.

0. By heating a mixture of an aromatic sulfonic acid and an alkylolamide of a fatty acid to 270 C. with the removal of water.

Example 10 A mixture of 330 grams (1 mol) of ethanolstearamide and 190 grams (1 mol) of p-to1uene sulfonic acid monohydrate was heated to 270 C.

in a short-neck flask fitted with a distilling con-- Example 20 Same procedure as Example 10 using 347 grams (1 mol) of the crude ethanolamide of cottonseed oil fatty acids (made by heating 286 grams of cottonseed oil and 61 grams of monoethanolamine to 210 C.) and 190 grams (1 mol) of p-toluene sulfonic acid monohydrate. Again 36 grams -(2 mols) of water was obtained and the product was quite similar to that obtained in Example 1a.

It is not necessary to use a full mol of the sulfonic acid per mol of amide to obtain the oxazoline. The use for instance of /2 mol of sulfonic acid per mol of amide will yield a mixture of equal parts oxazoline salt and free oxazoline.

Other carboxylic acids which may be used in place of all or part of the fatty acid in the above example, are capric, palmitic, stearic, oleic, abietic, montanic, naphthenic acids, talloel acids, mixtures of such acids and especially mixtures of acids obtainable by saponiflcation from coconut oll, palm kernel oil, cottonseed oil, or from any of the various other vegetable or animal oils and fats.

Likewise, various other organic sulfonic acid salts of amino alcohols may be used in place of all or part of p-toluene sulfonic acid salt of monoethanolamine in the above example, and

the invention is not limited to those of a particular series. 'Iiius. for example, in addition to the common aromatic sulfonic-acid of the benzene series employed in the example, those of diphenyl, naphthalene, threne series may be used. The aliphatic sulfonic acids. may likewise be employed such as those of paramn hydrocarbons of l2-18.carbon atoms in length, llgninsulfonic acid, guanyl urea sulfonic acid, dodecyl sulfonic acid, and the like, also compounds such as toluene thiosulfonic acid.

It will be noted that the products obtained by either method are sulfonic acid salts of.

Monoethanolamine is the preferred alkyloamine because of its cheapness and ready availability. It should be distinctly understood, however, that the monoethanolamine may be replaced in all or part by other primary alkylolamines and products obtained having valuable silica promoting properties. Representative allnvlolamines include those such as: monoisopropanol amine, mono-n-propanol amine, 2-aminol-butanol, 2-amino-2-methyl propanol, Z-aminol-hexamol, 2-amino-2-methyl 1,3-propanediol, 2 amino-l-butanol, and the like.

These aromatic sulfonic acid salts of oxazolines (prepared according to the foregoing examples) may be distinguished from the arcmatic sulfonic acid salts of monoethanolamine esters of fatty acids (prepared by Method A, but heating to not over 250 C.) by the fact that they are not decomposed by heating with aqueous solutions of strong alkalies, whereas with similar treatment the ester salts are hydrolyzed to soaps.

The reagents of the present invention are effective promoters or collectors for negatively 1 charged or acidic ore materials generally and said acidic material may either be worthless gangue or valuable ore constituents. The most important uses are, however, in connect-ion with the froth flotation of silica from non-metallic ores in which the silicious gangue may represent a minor proportion of the ore rather than metallic and sulfide ores in which the gangue usually represents the major proportion of the ore. Representative acidic ore materials are the feldspars, quartz, pyroxenes, the spinels, biotite,

muscovite, clays, and the like.

While as stated heretofore, the present invention is not limited to the treatment of any particular ore material, it has been found to be well suited for froth flotation of silica from phosphate rock and is the preferred embodiment of the invention. In the processes of removing silica from phosphate rock, the conditions are such that practically complete removal of the anthracne, I phenansilica must be accomplished in order to produce a salable phosphate material. It is therefore an advantage of this inventionthat our reagents not only effect satisfactory, removal of the silicav but are also economical-in amounts used. The quantities required range from 0.2 pound to 2.5 pounds per ton of ore depending upon the particular ore and the particular reagent. The invention is not, however, limited to such quantities.

The reagents of the present invention may be used alone or in mixtures with other promoters. They may likewise be used in conjunction with other cooperating materials such as conditioning reagents, oily or fat materials such as hydrocarbon oils, fatty acids, or fatty acid esters.

These new reagents are also adaptable for use in any of the ordinary concentrating processes such as film flotation, tabling, and particularly in froth flotation operations. The ore concentrating processes employed will depend upon the particular type or kind of ore which is being processed. For example, in connection with phosphate rock, relatively coarse phosphate bearing material, for example, 28 mesh and larger, can be very economically concentrated by using these reagents in conjunction with a material such as fuel oil or pine oil and subjecting to concentration by the use of tables or by film flotation. The -28 phosphate rock material is best concentrated by means of froth flotation employing these improved silica promoters.

When the reagents oi the present invention are employed as promoters in the froth flotation of silica from phosphate rock, which is the preferred embodiment thereof, the condition may be varied in accordance with procedures known to those skilled in the art. The reagent may be employed in the form of aqueous solutions, emulsions, mixtures, or solutions in organic solvents, such as alcohol and the like. The reagent may be introduced into the ore pulp of the flotation cell without prior conditioning or they may be conditioned with the ore pulp prior to the actual concentration operation. They may also be stage fed into the flotation circuit.

Other improved phosphate flotation features which are known may be utilized in connection with the present invention such as splitting the phosphate flotation feed into a plurality of size ranged and floating each size separately as described in the U. S. Patent No. 2,156,245, the very complete removal of the slime prior to flotation which is also an aid to better results as pointed out in the Erickson application Serial No. 325,011, filed March 20, 1940, and the Mead and Maust application Serial No. 320,121, filed February 21, 1940, which describes a process for classifying and desliming phosphate flotation feed by means of a hindered settling classifier and which deslimed feed is well suited for treatment in accordance with this invention.

This invention will be further illustrated by the following specific tests which are illustrations of the preferred embodiments thereof, but is not to be strictly limited thereby.

Flotation tests as follows were made on a sample of Florida phosphate ore from the Old Colony mine near Brewster. This ore material, which was essentially 48 +200 mesh material was agitated and scrubbed with water to break up the clay balls. The slimes were subsequently removed by decantation and washing repeated until the ore material was substantially free of slimes.

SeparateBOOgramsa-mplesofthedeslimedflotation feed were diluted to solids with water test products were then filtered, dried, weighed 10 and assayed. The metallurgical data obtained in these tests are presented in the following table.

3. In ore concentrating processes, utilizing differential surface wettability principles of ing acidic silicious gangue from non-metallic ore constituents,-the proces which comprises carry- 5 ing out the concentration operation in the presence of a product produced by heating a mixture of a primary aromatic sulfonic acid salt of an alkylol amine and a fatty acid at a temperature above 250' C.

,4. In ore concentrating processes. utilizing differential surface wettability principles of separating acidic silicious gangue from non-metallic ore Table Concentrate 'lailing 2 Insol. D Pramoter Weight Insol. Wc sht Insoi.

5 2; dfi l: u g 37 37 Page; f The act bts it of 1 o ined yheatingamrure toluene mmaeimcoconutoilhttylcida andmo 2 5542 04.84 34.5: new $5.10 114 110 Thermdnct h tained b beatini land toiue o y am no c n ie aeidsaltg iiiiaiioethan ilalninsand acids 3...--. 55.42 63.52 as; 08.50 36.48 2.27 1.50 The net obtained hyheatingamixturaof benrene -monicacidalmonogtg7arm l aminsandtalloelacidstoa 4 55.42 62.14 87.03 98.59 37.86 2.00 1.41 'lheprodnctob l ay a madeugof ghs sulfonicaeidineqnalmo o porflom. n 5 55.42 61.24 80.20 $.66 38.76 1.02 1.34 Theroductobtainodbyheatinga 'madeupofl mo.of monoe lamide ccttonssedoilfatty acidsandifimolofptoiuenesulfonicacidtoatempen- 43 8703 3.72 3757 IN 128 T fi btningl b heating oil 0 55.42 62. o y a v acidlan l mol ofptoluene sulf iii dto a peraac tureofaboutam'c m While the foregoing examples relate to the sel aration of quartz from phosphate bearing material the invention is not limited thereto. Good recovery and separation are also obtained using ourreagents and reagent combinations in connection with other silicious acidic minerals, for example, the separation of feldspar from quartz, mica from quartz, mica from cement rock and -thelike.

This application is a continuation in part of our co-pending application Serial No. 326,953, filed March 30, 1940.

We claim:

1. In ore concentrating processes utilizing differential surface wettability principles of separating acidic silicious gangue from non-metallic ore constituents, the process which comprises carrying out the concentration operation in the presence of at least one of the products obtained by a method of the group consisting of, reacting a mixture of a primary alkylol amine, an aromatic sulfonic acid and a higher fatty acid by heating at a temperature above 250 C., reacting a mixture of an aromatic sulfonic acid salt of a primary alkylol amine and a fatty acid by heating at a temperature above 250 0.. and by heating a mixture of a primary alkylol amide of a higher fatty acid and an aromatic sulfonic acid at a dehydration temperature.

'2. In ore concentrating processes, utilizing differential surface wettability principles of separating acidic silicious gangue from non-metallic ore constituents, the process which comprises carrying out the concentration operation in the presence of a product produced by heating a mixture of a primary alkylol amine, an aromatic sulfonic acid and a higher fatty acid at a temperature above 250 C.

. l Reagent combination consisted of0.5 lb. momoter per ton ofore and0.l2 lb. pine oil frother per tonofom.

constituents, the proces which comprises carrying out the concentration operation in the presence of a product produced by heating a mixture of a primary alkylol amide of a higher fatty acid and an aromatic sulfonic acid at a dehydration temperature. 5. In ore concentrating processes, utilizing differential surface wettability principles of sep- 45 arating acidic silicious gangue from phosphate rock values, the process which comprises carrying out the concentrationoperationin the presence of a product produced by heating a mixture of a primary alkylol amine. anaromatic sulfonic acid and a higher fatty acid at a temperature above 250 C.

6. In ore concentrating Processes, utilizing differential surface wettability principles '01. separating acidic silicious gangue from phosphate rock values, the process which comprises carrying out the concentration operation inthe presence of a product produced by heating a mixture of an aromatic sulfonic acid salt of a primary alkylol amine and a fatty acid at a temperature above 250 C.

'7. In ore concentrating processes, utilizingdif- I ferential surface wettabllity principles of separating acidic siliciousgangue from phosphate rock values, the process which comprises carrying out the concentration operation in the presence of a product produced by heating a mixture of a primary alkylol amide of a higher fatty acid and an aromatic sulfonic acid temperature.

8. In froth flotation process of separating acidic silicious gangue from non-metallic ore values, the process which comprises subiecting the ore to froth flotation inthe presence of a product obtained by heating a mixture of a pri- 7 mary alkylol amine, an aromatic sulfonic acid separatat a dehydration 215161 a higher fatty acid at a temperature above 9. In froth flotation process of separating acidic silicious gangue from non-metallic ore values, the process which comprises subjecting the ore to froth flotation in the presence of a product obtained by heating a mixture of an aromatic sulfonic acid of a primary alkylol amine and a fatty acid at a temperature above 250 C.

10. In froth flotation process of separating acidic silicious gangue from non-metallic ore values, the process which comprises subjecting the ore to froth flotation in the presence of a prod uct obtained by heating a mixture of a primary alkylol amide of a higher fatty acid and an aromatic sulfonic acid at a dehydration temperature.

11. In the froth flotation process of separating acidic silicious gangue from phosphate ore values, the method which comprises subjecting the ore to froth flotation in the presence of the reaction product obtained by heating the benzene suifonic acid salt of monoethanolamine with coconut oil fatty acids at a temperature of about 270 C.

12. In the froth flotation process of separating acidic silicious gangue from phosphate ore values, the method which comprises subjecting the ore to froth flotation in the presence of the reaction product obtained by heating a p-toluene sulionic acid salt of monoethanolamine with coconut oil fatty acids at a temperature of about 270 C.

13. In the froth flotation process of separating acidic silicious gangue from phosphate ore values, the method which comprises subjecting the ore to froth flotation in the presence of the reaction product obtained by heating a p-toluene sulfonic acid salt of monoethanoiamine with oleic acid at a temperature of about 270 C.

DAVID WALKER JAYNE. JR. STEPHEN EDWARD ERICKSON. HAROLD MILTON DAY. 

